I. Field of the Invention
This invention relates generally to apparatus for storing a step ladder or extension ladder on the cab of a semi tractor, and more particularly to a ladder holder that when actuated, it delivers a stored ladder to a location accessible to a person standing on the ground alongside of the semi tractor.
II. Discussion of the Prior Art
Semi tractor and trailers carry lighting that periodically needs servicing. When it is considered that the overall height of a semi tractor and trailer is approximately 13 ft. 6 in. so as to comply with interstate highway bridge standards, it becomes necessary for the operator to have a ladder available in order to be able to reach lights atop the cab or trailer.
The fuel efficiency of semi-trucks is influenced tremendously by aerodynamics. Most of the power generated by a semi tractor is utilized to overcome drag forces while operating at highway speeds. Aerodynamic fairings have therefore become standard equipment on modern tractors.
The gap between the tractor cab and its trailer is a high drag region that is typically streamlined by providing tractor side panels as fairings that attach at the rear end of the cab along the sides thereof. Such side panels help prevent the air from entering the area between the cab and semi-trailer, thus substantially reducing the drag coefficient. It has been found that providing tractor side panels can yield a fuel saving of 0.7% for an articulated vehicle.
These tractor side panels must not interfere with the semi-trailer turning. To minimize the gap, rubber strips can be fitted onto the trailing edges of the tractor side panels, thus extending them and reducing the gap to the maximum extent while still not interfering with the turning ratio of the trailer.
FIG. 1 is a rear view of a semi tractor cab showing side panels 1 and 2 on the rear driver's side and rear passenger's side of the cab 3. Also shown is a prior art ladder holder being used to support an extension ladder 4 against the rear surface of the cab 3.
It should be apparent from this view that in order for a person to access the ladder, that person must climb up upon the tractor's platform 5 (FIG. 2) to which the vehicle's two rear drive axles are journaled at a location just forward of its fifth wheel coupler 6. This area is often slippery due to accumulated grease and road dust, creating a hazard for the person seeking to remove or replace a ladder onto the rack on which it is normally stowed.
It would therefore be advantageous to have a ladder holder attachable to the rear surface of a semi tractor cab and that will make the ladder readily accessible to a person standing on the ground alongside the cab, thereby obviating the need to climb up onto the tractor platform 5 in order to gain access to the ladder. The present invention provides such a ladder holder.